1. Field of Invention
The present invention relates generally to the area of electronic control centers used within intrusion (burglar) systems and more particularly to a uniquely packaged control center imbedded within a hermetic hard plastic encapsulation as a protection against tampering and attacks against the alarm system by an intruder.
2. Prior Art
It has become customary to mount the electronic circuitry of a control center of an intrusion center inside a steel enclosure or cabinet, which is physically locked to prevent unauthorized personnel from having access to the circuitry with the steel cabinet being normally equipped with a switch which causes an alarm if the cabinet or box is opened while the system is enabled.
In the beginning, electronic control panels for burglar alarm systems relied upon relay logic. Foil was placed on windows and switches on doors as well as trap wiring around skylights, air conditioning ducts and the like, all of these areas of surveillance being connected in series into a large closed circuit loop. A battery and relay coil were wired into the loop so that the relay would be normally energized, until the loop was broken somewhere by opening a door, breaking a window, etc. When broken, the relay would become de-energized causing a normally open switch to close and an alarm to sound or a telephone call to be made to the police station. A holding contact on the relay was used to hold the relay in the alarmed condition until it was subsequently reset by the owner. While this simple system (which has been and continues to be widely used) has been replaced to some extent by more sophisticated circuitry, problems have persisted. Typically, the alarm is triggered by the owner leaving the premises, unless a key switch with a delay or located outside the building is used. Inside the building, the control center must be protected from tampering by an experienced burglar, which has heretofore been attempted by hiding the control center or enclosing it within the mentioned metal cabinet or box. Troubleshooting the system and locating malfunctions and/or a specific area of surveillance which has been invaded by an intruder has been extremely difficult in complex installations. Normally, special test equipment is required. In the past, prior art alarm systems, when enabled and a door or window has been left open, will issue an alarm usually resulting in a visit from the local police. In the past on many occasions intruders will enter a business during the day when the business is open and the alarm system shut down, and with fingernails or a sharp object scratch the protective foil on the windows or sever a conductor at some other location so that the alarm system cannot be turned on without causing alarm. If the owner elects or is required to defer repair of the system until the following day, the burglar will be undetected that evening. With systems of the prior art when a false alarm occurs, the police or other personnel cannot gain access to the building and the alarm continues to sound until the batteries go dead or until someone puts a ladder against the side of the building and cuts the system's wires, permitting subsequent access to the building by burglars that evening.